1. Field of the Invention
This invention relates to a method for raising a sunken ship, and generally any object lying on the bottom of the sea, a river or a basin.
2. Discussion of the Prior Art
To allow for raising sunken ships, wrecks or other objects which lie on the bottom of a basin, for example a sea or river bottom, by means of jigs, pontoons or other floating equipment with hoisting apparatus, it is generally required to arrange hoisting slings, cables, chains or similar devices underneath the wreck. The wreck secured in this way to hoisting cables may then be raised out of the water by means of the required hoisting appliances.
A technically-impracticable method for raising wrecks is disclosed in German Patent No. 828,068. According to this method and by means of the device provided therefor, it is proposed to drive strongly-curved tubes from an underwater-dwelling apparatus, underneath the wreck and to pull a cable through said tubes.
First of all, operating from an underwater-dwelling apparatus, which has to insure propulsing said curved tubes, is a very inconvenient and in actual practice under many conditions, an impracticable assignment.
Secondly, it is necessary to work with strongly-curved tubes; and due to the previously-selected curvature radius of said tubes, it is always necessary to bore to some depth when a required width or distance is to be obtained. With wide wrecks, it will also be required to bore more deeply, which makes adapting the boring depth to the geological conditions impossible.